M.Cachiio,A.Oiiveira,J. Vitorino: Subtropical winter guestS, Porrugal, p. 19 - 26.

Journal of Nannoplankton Research, 22, 1, 2000.

SUBTROPICAL WINTER GUESTS, OFFSHORE PORTUGAL
Mdrio Cachiio*, Anabela Oliveira** & Joiio Virorino t*Dep. Geologia Faculdade de Ciencias Universidade U sboa, Rua Escofa Politecnica, #58, P-1294 Lisboa
CODEX, Portugal, mcachao@jc.ul.pt**JNICT, Universidade do Algarve/Marinha-lnstituto H.idrogrdjico, Rua das Trinas, #49, P-1200 Lisboa, Portugal.
aboliveira@mail.telepac.pt
t Marinha-lnstituto Hidrogrdfico, Rua das Trinas, #49, P-1200 Lisboa, Portugal

Abstract: Coccolithophore communities developing off Portugal during November, 1996 were composedof species from both temperate (influenced by ENACWp) and subtropical (influenced by ENACWT)
regions. The first group includes Gephyrocapsa mue//erae, G. ericsonii and Emiliania huxleyi. Membersof the second group include (for 5m water-depth samples) Alisphaera spatula, Calcidiscus leptoporus,
Coronosphaera mediterranea, Discosphaera rubifera, Gephyrocapsa ocecmica, Polycrater galapagensis.
Rhabdosphaera clavigera, Syracosphaera pu/chra. S. molischii. Umbilicospha era sibogae andUmbellosphaera tenuis, some o f which are typical of s ubrropical upper photic zone water-masses.
Deeper-water samples (betwee n 75 and 85m wa ter-depth) showed the presence of Algirosphaera
quadricomu, Alveosphoera bimurara. Cyclolirlws anulus. Florisphaera profunda, Michaelsarsia elegans,
Syracosphaera lamina and Turrilitlws latericioides; s pec ies typica l of subtropical middle and lower
photic zone water-masses. The presence of these subtropical assemblages duri ng the end of summer autumn is taken as direct evidence that at least 120 to 220m of the uppermost part of the water-column
is sourced from S of the Azores Front and fed into the Portuguese s lope poleward current system.

Introduction
The GuJf Stream system i s the dominant feature of N
Atlantic surface circulation at present and probably has
been since the closing up of the Isthmus of Panama at theend of the Early Pliocene. Deflected NE by the eastern N
America coast, the tropical waters subdivide before
crossing the Mid-Atlantic Ridge to form the N Atlantic
Current, N of 46°N, and the less well-defined Azores
Current, between 32° and 36°N (Pollard &Pu, 1985; Klein& Siedler, 19:89). The Azores Current thermohaline front
occurs between 35° and 36°N, in closeproximity to a deep
chlorophyll maximum, and when it reaches the surface

during winter it can tilt towards theN (Stramma & Muller,1989). At Central Water depths, eastern N Atlantic watersof subtropical origin (ENACWT), formed along the Azores
Front, were shown to occur off the Portuguese coast, overLhe southward-flowing waters of s ubpolar origin(ENACWp) (Fiuza, 1984). At the surface, branches of the
Azores Front can probably feed warmer and saltier waters
into the fberian slope poleward-flowing current (thePortuguese Coastal Countercurrent - PCC: Fiuza et al. ,submitted), observed during the winter both by infrared
satell ite pictures and in situ hydrograph.ic data (Frouin etal., 1990). Betwee n April and September (summer

4~ ~------~------~------~--------~------~----~~'ENACWp~

N

CUMA/97.....

IberianPeninsula

AzoresIslands

3fflW
Figure 1: Water and CTD sampling station location map. with Transect I (TI , Stations I to 19), Transect 2 (T2. Stations 19 to 29) andTransect 3 (T3. Stations 34 to 44) sampled during the CORVET 96 cru ise. Dashed square displays the sampling area during the CUMA/
97 cruise. Main oceanographic current patterns in the eastern Atlantic Ocean: ENACWr - eastern N Atlantic Central Waters of subpolar
origin; ENACWT- eastern N Atlantic Central Waters of subtropical origin. AZOR 87, AZOR 89 - reg istered trajectories of the kzores
Current during 1987 and 1989 IPIMAR cruises. (Adapted from Rios et al., 1992; Dias er aL, 1990).

19

Joumal of Nannoplankton Research. 22, I,:woo.

M.Cachiio,A.Oiiveira,J. Vitorino: Subtropical winter guests, Portugal, p. 19- 26.

conditions), upwelling develops off Iberia (Wooster et al.,I976) thus overplinting this pattern.

Material and methods
For the present s1tudy, 18 samples were collected during
the CORVET (, Corrente da Vertente') cruise of theInstitute Hidrogriifico in November, 1996, off the western
Portuguese coast (Figure I). Duting the tlrst phase of thecruise, from 2nd.- 5th November, a regional study was
conducted during which hydrographic and nephelometricmeasurements were obtained along an open ocean
meridional (N-S) transect at I2°W (TI) and along two zonal
lransects, E-W from the shelf to open-ocean: one at about
36°N, between Cape St Vincent and the Gorringe Bank(Tl) and the other at41 °30'N (T3). A complementary set of
14 samples was also studied from a second cmise (CLIMA),
collected from a mtore-restricted area over the northern shelfofPottugal (see CUMA/97 in Figure I). The CLIMA cruise
was conducted during December of 1997, when
oceanographic conditions were reflecting a more-typicalwinter regime. The data were obtained with a Neil Brown
MK Ill-C CTD •equipped with a nephelometer. Water
samples. both for CTD calibrations and for suspended
particulate matter evaluations. were obtained with a 12bottle rosette sys tem. Onboard ship, 2 to 5 litre watersamples were filtered through HA Milliporc membrane
ftlters (0.45!Jm) with a vacuum pump. A direct pressure
system was used for sutface samples taken at 5m waterdepth. Additional sets of deep-water filters were preparedat stations with water depths over 3 OOOm. Thi s lower setof samples was colJected at the maxi mum nepheloid layer(around 70 to 80m water-depth). During the CLIMA cruise,an additional set of samples were coUected at 30 and 80m.
On samples from the CORVET cruise. coccosphereabundances we:re estimated by using an optica lpetrographic microscope (1250x magnification) on a total
observed area b•etween 1.5 and 4mm2 of eac.h filter,
depencling on the: general abundance. On samples fromthe CLIMA criUise. coccosphere abundance wasdetermined by SEM on a total area of 0.5mrn2 (24photographs with 750x magnification). The raw countvalues were converted to cells per litre based on area
counted and volume of water filtered. A total of 16 major
taxa were identified and counted on the petrographic
microscope. Subsequent observation of selected samplesof the CORVET cruise, and of all samples of the CUMA
cruise, by SEM increased the total number of recognised
species to 48 (see Taxonomic Appendix. below).

pressure region was located off the western Portuguese
coast, extending over Iberia, inducing upwellingfavourable winds. Events of intensification and decay ofthese upwelling conditions, w1tb a time-scale of several
days, were associated with the changing positjon of thehigh-pressure region. The expression of these events on
the sea-surface temperature was followed before andduring the cruise with satellite images kindly provided by
the Remote Sensing Data Analysis Service of the Plymouth
Marine Laboratory. These images reveal that Tl (Cape St.
Vincent-Gorringe Bank transect) was sampled during the
decay phase of a 4-5 day upwelling event. The upwelling
conditions just before the beginning of the regional study
are clearly revealed in the satellite image for the 1st
November (Figure 2A), as a band of cold water along thewestern Iberian coast. At some locations, this coastal bandof cold water extends offshore, in the form of upwellingfilaments, reaching the continental s lope region.
Hydrographic fields reconstructed from in situ CTD dataalso detected the upwelling concli tions revealed by satellite
images.
Along T2. Stations 21 and 23, located S of 38°30'N,
showed so·oog contributions of ENACWT. con-espondjng
to the high temperature and salinity branch of the ENACW

J:<'i~:ure .ZA (llbove 1:!-)mellile image during I he<'<)RVET crlli:.e.
!si November. 1996

Physical study
Fiuza (1984) showed that there were two main sources for
the ENACW off the Atlantic NE ~oast of Portugal: a)
subpolar modal water formed by deep winter convection,
N of 50°N, and advected southwards- which we will callthe subpolar con:tribution, ENACWp; and b) eastem N
Atlantic water - which we will call the subtropicalcontribution, ENACWT- formed along the Azores Front
during winter and advected eastwards (Figure I).
Duting CORVET 96, the study was conducted at theend of a period of almost one month during which a high-l'igurc 211 llefl):
Satellite imngc of 1hesampling ar.~n I non hem
Pnnugue:;e :.helf: :.ee Fig. I 1
during I he CUM/\ crui:.e.
(Kindly provided by lllC
Remote Sensing D:ua
Analysis Servil-e of the
J>lymoulh Marine Laborntory)20

M.Cttchiio,A.Oiivcira,J. Vlrori11o: Subtropical winter guests, Ponug.al, P• 19- 26.

The situatio111 is radically changed at the stations in thenorthward region (25 and 28), which have a lower
contributiou f rom the subtropical branch of ENACW anda greater contribution from the ENACWp branch. A sharp
temperature/salinity transition e.x.ists at Station 25 between
the northern and southern areas. A comparison of thehyd(ographic data with the corresponding sea-surface
temperature field obtained from remote sensing, s uggeststhat this anomalous region probably results from theintrusion of water from the northern area across the warms urface-waters located S of 39°N . A second aspect is thefact that the rapid surface transition observed at Station
25 has a subsurface expression, with a change in watermass characteristics at depths between 100 and 500m.
These are depths influenced by the N Atlantic Central
Water (NACW).
A region of high salinity (maximum of36.0%&at about
70m de.pth) is observed in the upper 300m, about 20 to
40km offshore from the shelf edge alongT3. This region
corresponds to the PCC which Frouin et al. (1990) and
Haynes & Barton ( 1990) have shown to occur along thenorthern Portuguese coast in winter. Direct current
observations over £he northern Portuguese slope haverevealed that. during upwelllng conditions, the surface
expression of the PCC was replaced by the equatorward
jet associated with the upwellingregime ( Yitorino. 1989:
Silva, 1992). This seems to be the situation observed during
this transect, which took place in weak upwelling
conditions.
The CLTMA 97 cruise sampled a restricted area on thenorthern part of the Portuguese shelf in which general
condjtions could be characterised as typical winterconditions. in which there was a highly variable windregime, with sustained periods of winds with a southerly
component (Fiuza et al., 1982). During this period there
was invasion of the shelf by wann oceanic waters, due tothe prevailing downwelling conditions. Offshore waters
were abnost completely mixed with coastal waters. being
those coastal waters largely influenced by 1ocal river runoff(low salinity and low temperature values in the upper 25m
layer) (Figure 28).

Coccolithopbore Results
COR VET cruise
In the upper water-column layer (5m), mean total4
coccolithophore standing crops were about 1.8xJ 0 cells
1
2
r , ranging between 3.4xl0 (Station 43) and 8.4xl04 cells
r 1 (Station 1) (for locations, see FigLu·e I).
Thecoccolithophorecommuuity present in our samples(members of which are illustrated in Plate I) included theglobal and opportunistic species, Emiliania huxleyi. with
3
1
values ranging from <100 to 8. 1xl0 cells r (Station 1).
Also present in most of the samples are the species
Gephyrvcapsa ericsonii and Gephyrocapsa muellerae,
33with values reaching 30.8x.l0 (Station 1) and 2lx.10 cells
1r (Station 34), respectively, closer to the upweiJjng inner
regions, The latter species bas ab·eady been recognised intemperate water masses (Jordan in Jordan & KJeijne, 1994)
and is used as an indicator of the temperate biogeographic
coccolithophore zone (Zone 2 of Mdntyre & Be, 1967;

Journal of Nannoplankton Research , 22, I, 2000.

Winter et al.. 1994). Helicosphaera carteri was also present
1
but in smaller numbers (<;500 cells r ). Coccolithus
pelagicus, a species that is commonly found in subarctic
cold water-masses and in upwelling areas (Cachao & Moita,
in press), was recorded at only one station (Station 1) and1
in low numbers (< I 00 cells 1" ). However, species generally
related to warmer (subtropical) water-masses were also
fo und . These included: Umbellosphaera tenuis ,Umbilicosphaera sibogae, Discosphaera tu.bifera,
Rhabdosphaera clavigera var. clavigera, R. clavigera var.
stylifera, Calcidiscus leptoporus and Gephyrocapsa
oceanica. Absolute abundances for these and otherspecies, determined from 5m water-depth san1ples. arepresented in Table 1 (Cachiio er al .. 1998).
SEM examination of filter samples from Stations 1, 23
and 42 (5m water-depth) confirmed the presence of theprevious species, and others s uch as: Alisphaera spatula,Coronosphaera mediten·ahea, Polycrater galapagensls,
Syracosphaera molischii and Syracosphaera pulchra.
Among these species. D. tubifera, P galapagensis, R.
clavigera and U. tenuis are typical of the upper photic
zone (UPZ) of subtropical water-masses (R. Jordan. pers.
comm.. 1999; Jordan, 1988: Winter et al.. 1994). SEM
observations on ftlters from Stations 4 (75m water-depth)
and 4.1 (86m water-depth) also s howed the presence of
Algirosphaera quadriconw, Alveosphaera bimurata,
Cyclolithus nnulus, Florisphaera pmfundn var. elongata.
Michaelsarsia elegans, Syracosplwera lamina andTurrilithus latericioides. Of these. M. elegans prefers tolive in the middle photic t.one (MPZ) whereas A.
quadricorrtu , A. bimllrata. C. anulus. F. projimda, S.
lamina and T. latericioides all tend to live in the lower
photic zone (LPZ) of subtropical waters (R. Jordan, pers.
comm., l999: Jordan, I988;Wintereta/.. 1994).

CL/MA cruise
The coccolithophore mean average standing crop was
maximum at 1he surface, reaching, at 5m water- depth,1
2.7x1 05 cells f , decreasing to 2.5x I 0 5 cells r 1 at30m, andto less than hat f of the upper surface values ( 1.3x 105 cellsr 1) at 80m water-depth , Offshore samples (>45km fromshore) revealed higher standing crops than coastal ones.
although diversity was more or less COJistant (see Table 2).
The most abundant species found was G. ericsonii.
3
1
with standing crops ranging from 7 .9xl to 0.4x 10 cells r .
As in the previous cruise, the oppmiunistic species, E.
huxleyl, was also present in significant numbers (7 .3xl 0 4
34
to 0.4xl0 cells
as well as G. muel/erae (3.6x.10 to
31
1.1 X 1o cells r ). Subtropical s pecies were also found insignificant numbers. such as in the case of G. oceanica
44(3.4x10 to0.4xi03 cells
sibogae (3.7xl0 to 1.3xl03
1
3cells r ), S. pulchra (3.6 to 1.4xl 0 cells r\ Syracosphaera
41
spp. (5.1 x 10 to 0.9x103 cells r ) and D. tubifera (6.8 to
3
1
OAxi 0 cells r ). Scyphosphaera apsteinii was also
commonly found in these waters, with abundances ranging
from (1.4x 104 to 0.4x 103 cells r ').
A list of all the identified species in samples taken
during CORVET and CLIMA cruises is presented in theTaxonomic Appendix, below.

as

r\

r\ u.

21

M.Cadu7o.A.Oiiveira.J. Virorino: Subtropical winter guests. Portugal, p. 19 - 26.

Journal of Nannopllanktou Research, 22, I. 2000.
Station

I

4

6

8

14

16

Latitude37'01 .3'N

9'1>3.2'W

36"5J.2'N
9'42l'W
2050

36'48 2'N
10'06.0'W

tt•19.1W

l6"30.9'N
11"33.8'W

96

36"S7 1'N
9'21,6'W
1530

S6"33.8'N

LongiiUdc

2720

17.28
36.05
84

19.63
36.38
9

19.72
36.44

20.87

1327
20.16

20.04

36.59

36.46

36.42

0.8

0.6

10
2.3

8
1.1

1.0
0.8

7.0
0.2
0.1

I3

0.6

Max del!!J! !mlTemperature ("C)
Salioit~ (%olStandi os croe
C. /eplopoms
D. tubifera
G. ericsonii
G. muellerae
G. oceanica
E. huxleyi
H. carteri
R. clavigera
Syracosphaera spp.
U. sibogae
U. tenuis

31.5
30,8

7.4
8,1

16

0.7
I8

OA

0.7

2.4

18
0.4
11
11
04

ss

02
p

1.0

18

07
0.9
0. 1
4.3

0.8

13

0.3

3. 1

4.5

1.2

Ta ble l A: Data shl)et of coccolithophore absol ute abu1tdaoces (x 10' cells 1' 1) insamp les from surface-waters (5m depth) of the S transect. * = free coccoliths on ly:
P = rare occurrences (<lOO cells 1 ').
Station

21

23

25

28

Latitude37'1l4.7'N

l7'45.0'N

Lonsnuck
Max. dcethimj

12'UOSW

12'00.0'W

JS' 24 4'N
11' 594'W

39'24,5'N
12'\JO O'W

3010

5015

4850

4066

Temperature ("C)
Salini~ (%o)
Standi os croe
C. leploporus
D. wbifera
G. ericsonit
G. qmellerae
G. aceanica
E. lmxleyi
H. carteri
R. c/avigem
Syracosphaera spp.
U. stbogae
U. I€111//S

19.70
36.29
8

19.45
36.20

19 10

2.7

1.4

1.3
0.5
0.8
0,4
0.1
0.6
0.1
3.3
2.4

18 60
35.98
6
p
p
0.7
I6

3.8

76

18

0.9

p
p

0.4

0.7
1.9

0.3
0.9

22

0,2

species. So, the presence of several UPZ, MPZ and LPZ
subtropical species near the Portuguese shelf. during
winter, can only be understood if related to the PCC. The
presence of this subt,ropical communi ty close to thePortuguese shelf, at latitudes higher than 41 °N (when it isabsent from more-offshore oceanic waters even during
summer: Jordan, 1988). is direct evidence that, dwing winter,waters from S of the Azores Front are fed into the
Pottuguese slope area by the poleward current system.
Moreover, the subu·opical coccolithophores retain thetr
vertical community structure, with a diverse assemblageof LPZ species being recorded in the deeper samples (A.
quadricomu, A. bimuratu, C. anulus, F. profunda, S.
lamina and T. latericioides). So, at least the uppermost
120 to 220m of the subtropical water-column are driven
towards the PCC. Satellite imagery and surface drifter

36.08
19
0,6

0.4
03
10 8
1.4

0.5

Table lB: Data shee:t of coccoJ ithophore absolute abundances (x I O'
cel.ls t·') In sa mples from su rface-waters (5rn depth) of ~he N-Stransect. =free coccoliths Ollly; P = rare occu rrences (<100 cell s*1' ').

Stationbetween the temperate and subtn)picalcoccolithophore assemblages was
positioned more-or-less paralle l to theNazare Canyon (See Figure 1). However,Jordan ( 1988) and Winter et al. (1994)
showed that. off Portugal, subtropicalcoccolithophore assemblages could only befound , in the oceanic domain, S of the
Azores Front (i.e. at latitudes lower than36"N). ln Mediterranean waters, several ofthese subtropical coccolithophore species
can also be found (Kieijne, 1993). However,these waters outflow from the Gibraltar Strait
at depths (>400m) incompatible with thede velopment of these photosy nthetic

34

35

36

37

39

41

42

43

LatitudeLongitude
Max~ deelh ~ml

41 "24.6'N
8°49,2'W
38

41 "24.7'N
s•s4.9'W
66

41"24.7'N
9"02.0'W
9041"24.3'N
9°1 4.3'W

800

41"24.5'N
9°46,6'W
2618

41"24.6'N
10"30.9' W
3585

41"24.5'N!0•40.0'W
2410

41"24.6'N
l0°50.3' W
306 1

Temperature (OC)Salinity (%o)

15.09
35.32

15.33
35.46

15.40
35.48

15.82
35.83

17.71
35.89

17.37
35 .88

17.69
35.80

17.71
35.82

Standins. cro~

63

20

9

0

0

10
0.1
2.5
1.4

24
0.2
1.8
9.5

0.3

0.3
0.3
0.2

*

9.6

C leptoporus
G. er icsonii
G. muel/erae
G. oceanica
E. huxleyi
H. carteri
Syracosphaera spp.
U. sibogae
U. tem1is

*

*

3.0
20.9
32.0

7.0
6.2
5.0

*

1.2

"'
*
*

*

0.5
0.1
0.2

•

*

*

*

*

0.7

•

*
*

Table l C: Data she•!t of coccolithophore absolute abundances (x lO' ce lls I ' I in samples from surface-waters (5m depth) of the N trnnsect.
• = free coccolh hs only.

Discussion

studies (Fit!za et al., submitted) have not identified thisconnection. but this winter coccolithophore community
found in offshore Portuguese waters is direct evidence fora link between the Azores Front and the PCC. The presenceof the LPZ subtropical community off Portugal at shallower
depths ( -70-80m) than they usually appear in subtropicalwaters can be easily understood by the lower lightavailability during winter, together with lower water

The presence of B. huxleyi and G. ericsonii in waters off
Portugal was piredictable, given their cosmopolitan
disu-ibution. The !temperate species, G. muellerae, was also
expected to be pmsent since this area is under the direct
influence of the !ENACWp. in which il may codominate
with the previous species (Jordan, 1988: Winter et al.. 1994).
Mcl ntyre & Be ( 1967) considered that the transitio n

22

M.Coclriio,A.Oiiveirn,J. Vitorino: Subtropical wimer guests, Ponugal. p. 19 - 26.

s..-

Ill

La•l..ao>ii!Udc&1"2991'1
MO•'W

..l

30

~,

T-I'C\

s80n4l"llO'N
9'02'1W 9'1H'W
9<
aoo

41'29TN

16726
16801
IH81

30

80

S.IINI)'

1611l7

ISI'S

35793
35889

5
30
lW

7•
•t'19S'N
9'25 TW
lOll

69•t'298'N

IO'OOTW
JIOO

1.5 179
16541

3!879

J• liS
35529

JS,94036.007

108
1)6

))0

109

lO

128

lOO

)59)1

.a l'41l'N
09'19 2·w

104

09'23fTW

9J

120

411'11 O'N
4)

119
41'51 O'N

117
41'49l'N"'

41'4 1.ZW
OM9TW

08'$5 I'W

09'00 rw
16

09'10 I W
120

09'24.6'\11

14$6)

16..157

16021

16..411
16418
16445

41'4&.5'N

430

107S

IU)O

16197
161!1

16.<6)
16501
l6l4S

16.216

17046
15211

16.242
15295

IH9l

lll94
16196
16 4)0

ll8JJ
Jl9<4

ll798

3S.867
35897
3H70

32813

l!SSt
lS 178

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36003

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l$6

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..,...,99 ,.,100

4l'.&ll'N
~z-v.

30

16 &6916511
16166

36.024tO)

t04
41/'4II'N
8'$31W

Journal of Nannoplankton Research. 22, I. 2000.

)600<

use;

JS 76S

16744

911

lS.&SO

35.9SOS1Andmt\""'P(x l01celll 1)

s

10)

lO

lO

80

967

178
IOJ

69

m

K

52

IS6

120

84
9

89

ll

l i1ble 2A: Data sheet of the loc:uion. temperature. salinity and total coccolithophore standing crops (;dO' cells I ') in samples from Sm,
30m and 80m depths. CLIMA 97 cnnsc.

-~E ]

.:;

8

·~

.,

li

::::

~
-<>
-.1

69
74

77
80
82
93
99

~
-.1"'

.:J

e

.§
§

...:

30
80
5

30
80
30
80
5
30
80

4.8

6.8
3.3

I6

0.4

1.7

17

I7

1.6
1.7

1.7

17

5

5
30
80
30
80
30
80

]~

". ul Ci "'

.. .
.

0.4

30

120

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119

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~
u u

5

5

30
80
5
30
80

117

I
1 -~ ~
•

30
30
80
30
80

s

114

e

..
.
..
. .. .
.. . .
.
•.. . •.. . . .
.. . ..
. . .. •.•..
. .. •

100

104

s

1.7
1.7
3.4

0.6

1.7

3.4

1.7

.

.

-~

~

"'

~

:X:

<.:

~

~

1 ! . J 1 "" "" ""
.
.
.

tci

tj

tj

34.8
37.2
73.0
44.3

307 2
84.6
786.6
543.2

60.9
30.7
20.3
35.6

198
70 4
62 3
74.4

152

118

8I
6.5

95
32

18.6
8. 1
65.0
28.8
42.3
38.9
67.7
32.2
16.2
47.4
27.1
7.2
33.8
2.5
9.3
26.2
25.0
44.7
16.6
37.1
6,8
25 7
2.4

40.6
1.8
438.6
66.0
196.3
294.5
2826
208.2
50.5
162 5
49 I
32 5
95

34
2.7
18.1

14.2
10 2
366
19 7

tj

~

7.9

4. 1
3.2

•

~

..

1.4

32
13.5
27

8.2
1.7
9.0
4.1
0.4

0.9
1.8

5.4

~
~

~

14.2

23
50.9

14 8

85

3.2

.

1.6

11 .8
0.9
25.3

1.6
1.8

3.6

8.5

5.1

54
23 7
68
72
54

18
338
SI

1.7

. .
. .. . .
.
. .
.
.
.. .. .• .
•. .• •. ..• .
•

9.3
82

44.5

5.2
11 4
1.1
1.4
I2

13
2.3

I8

I7

06

0.6

1.6

8.6
0.9
1.4

1.9

2.8
1.1
I4
04

0.4

0.4

16 9
1.7

..
.

16.2
3I
24 6
1.7

•
•

54

34

3.4

34

3.4

..

. .
..
1.4

3.3

.•

2.8

..
.
•

3.4

35.5
5I

..
.

1.7

8,5

13.5
186

~
l

16

. .
..

.
. .. .• . .
. ••. .. • .• .
22.0
2.7
1.8

-~

j

. . . .•... ... .

85.9
223.2
123.3
171.9
72.7
20.3
48.7
0.4

-~

t
-~

.

1.7
1.4

1!

l.,
:::)

48
3.4
28.4
18.0
25.4
18.0
4.1
8.1
L7
2.7
16.2
16.9
11.8
35.5
33.8
3.4
12.6

3.4
13.5
5.4
2.7
1.3
9.3
13.1
28.3
22.3
20.1
12.8
2.2

. .

1.4
1.4

3.6

Table 2B: D:lla sheet of the coccohthophore absolute abundances {x l01 cells I 1) in samples from 5m. 30m and 80m depths. C LIMA 97
cru1se. •= free coccolitbs only.

1transparency ( mean turbidity values were 0.8mg r for theupper 5m layer off Portugal).
During the CUMA cruise, the subtropical-dominants pecies occurring off Portugal were not the same ones
that were more abundant during tJ1e previous CORVET
cru isc. While in Nove mber o f 1996. U. terwis and C.
leptoporus were the dominant warm-water forms. during
Decembe r 1997, U. sibogne was the most abundant
subtropical form. While during the CORVET cruise, there
was a clear dis tinction between two communities (anoffshore subtropical assemblage and a coastal temperatecommunity) during the C LfM A cruise these two
communities were mixed , re ac hing their maximum
development jo more-offshore waters. These differencesc an be attri buted to several causes: ( I ) the regional
oceanographic regime of offshore Portugal (the end o f an

upwelling regime during the CORVETcruise and a wintermode rate regime during the C L!MA cruise): (2) the
developmental history of Lhe subtropical coccolithophorecommunities transported eas tward along the Azores Front;and (3) Lhe physical local conditions o r the northern
Portuguese shelf, mainly the presence of a stratified, lowsalinity water-body from ri ver runoff.
T he presence of a warmer-water coccolithophorecommuniry off PortugaL associated with a winter (low tonon- up well ing conditions) and not w ith a summer(moderate to strong upwelliog conditions: unpublisheddata of the CODENET-li cruise, June J999) oceanograpltic
regime, has implications fo r the pal aeoceanographic
interpretations that may be deduced from calcareous
nannofossils in the geological record of western Iberia.
Following these findings, an increase in these warm-water

23

Journal of Nannoplankton Research. 22. I. 1000.

M.Cachiio.A.Oiivtiro,J. Virorino: Subtropical winter guests. Portugal. p. I 9 • 26.

Calcioso/enia Gran, 1911
C. cf. C. murrayi Gran, 1912
Family: COCCOLlTRACEAE Poche. l 913
Genus Calcidiscus Kamptner, 1950
C. leptoporus (MwT.ty & Blackman. 1898) Loeblich &Genu~

s pecies abundances in the geological record must be
interpreted as reJ'lecting an increase in the intensity/numberof SW winter wind-regime conditions. most of them reJated
to s torms. and not necessarily with regional climate
warming.

Genus

Conclusions
The coccolithophore community developing off Portugal
was found to be much richer than expected. with species
both from temJPerate regions (directly intluenced by
ENACWp) and subtropical regions (directly influenced
by ENACWT) dominating particular areas. or intermixing
in others. Among the first group. we found G. mue/lerae,
together with G. ericsonii and£. huxleyi. Members of theecond group present in the s urface-waters (Sm waterdepth) included A. spatula, C. leptoporus, C.

Genus
Genus
Genus

Tappan, 1978
Coccolitlnrs Schwartz. 1894
C. pelagicus (Wallich. 1877} Schiller, 1930
Cyclollthus Kamptner. 1948 ex Detlandrc. 1952
C. anulusLecal. 1967
Oolirltows Reinhardt. 1968
0. sp.
Umbilicosphaera Lohmann, 1902
U. sibogae var. sibogae (Weber-van Bosse. L90 l)
Gaarder. 1970
U. sibogae var. fnliosa ( Kamptner, 1963) Okada &Mclntyre. 1973

Family: NO'£LAERHABDACEAE Jerkovic, 1970
Emiliwria Hay & Moh1er. 1967£. /wxleyi (Lohmann, 1902) Hay & Mohler. 1967
Genus Gephyrocapsa Kamptner, 1943
G. ericsonii Mdntyre & Be. 1967
G. muellerae Breheret, 1978
G. oceanica Kamptner, 1943
G. omata Heimdal, 1973
Family: HE LICOSPHAERACEAE Black, 1971, emend.
Jafa r & Martini, 1975
Genus
Helicosplwera Kamptner, 1954
H. carreri var. carzeri (Wallich, 1877) Kamplner, 1954
Family: PONTOSPHAERACEAE Lemmermann, 1908
Genus Scypltosplwera Lohmann. 1902
S. apsteinii var. apsteinii Lohmann. 1902
Family: RHABDOSPHAERACEA Haeckel, 1894
Genus Acanthoictl Lohmann. 1903 emend. Schiller, 1913.

mediterranea, D. tubifera. G. ocecmica, P. galapagensis.
R. c/avigera, S. pulchra, S. molischii, U. sibogae and U.
terwis, some of which are typical of the UPZofsubtropicalwater-masses. Deeper-water samples (75 to 85m) contain
A. quadricorrw, A. bimurata, C. anulus, F. profunda, M.
elegans, S. lamina and T. latericioides. The presence ofGenus

this subtropical community so close to the shelf, and atlatitudes higher than 41 ° N, appears tO provide s trong
evidence that, during winter, waters from S of the Azores
Front are fed inl<;t the PCC. Indeed. s ince a subtropical LPZ
coccolithophore community s tructure could be recognised,
we can infer that at least the upper 120 to 220m of thesesubtropical surfatce-waters are drive n towards the PCC.
Acknowledgements
The authors wish to express their thanks to Richard Jordan
for helping to make species determinations by SEM. forproviding data o n coccolithophores from the Azores Front,
for fruitful discu:;sions, and for a preliminary review ofd1e
manusc1ipt. The manuscript also benefited from the criticalreviews of Jcremy Young, Karl Baumman, Jose-Abel Aores,
Paul Bown. Jorge Silva a11d Aurora Rodrigues. whom theauthors also thank. This research was s upported by Centro
de Geologia of t·he University of Lisbon (Proxypal) and
PRAXIS XXI (lFCT). The Museu Nacional de Hist6ria
Natural da Universidade de Lisboa. Tnstituto Hidrognifico,
UCTRA (University of Algarve). and the Plymouth Marine
Labo ratory also provided logistic support during rhe
present rcscarclh. This paper is a contribu tion to the
CODENET EC network, and constituJes conrribution #A144 of the DrSEPLA Group and contribution #25 ofPALEO(Grupo de Paleontologia do Museu Nacional de Hist6rla
Natural).

Genus

Genus
Genus

emend. Kleijne, 1992
A. quallrosphina Lohmann. 1903
Algirospltaera Schlauder, 1945 emend. Norris, 1984
A. quadricomu (Schiller, 1914) Norris. 198~
A. robusw (Lohmann, 1902) Norris, 1984
Discophaera Hacckel, 1894
D. tub((era (Murray & Blackman. 1898) Ostenfeld,J900
Rhabdnsphaem Haeckel, 1894
R. clavigera var. c/avfgera Murray & Blackman, 1898
R. clavigera var. Sl)'l((era (Lohnmann, 1902) Kleijne &Jordan, 1990

Family: SYRACOSPHAERACEAE Lemmermann, 1908
Alisphaera Heimdal, 1973 emend. Jordan &GenusChamberlain. I993
A. capulata Heimdal, 1981
A. ordinata CKamptner. 1941) Hcimdal. 1973

Genus

Genus

laxonornicAppend~

Division: HAPTOPHYTA Cavalier-Smith. 1986
Class: PRYMNESlOPHYCEAE Hibberd. 1976
Order: PRYMl\IESIALES (Fritsch) Papenfuss. 1955

Genus

Genu~

Family: BRAAIRUDOSPHAERACEAEDeOandre, 1947
Genus
Braarudosphaera Deflandre, 1947
B. bigelowi (Gran & Braantd. 1935) Detlandre. 1947
Family: CALCIOSOLENIACEAE Kamptner.l937
Genus Anoplosolenia Det1andre, 1952
A. brasillensis (Lohmann. 1919) Detlandre. 1952

Genus

Genus

24

A. spmrtla Steinmetz, 1991
A. tmlcomis Okada & Mclntyre, 1977
Alvetlsphaera Jordan & Young. 1990
A. bimurata (Okada & Mc1ntyre, 1977) Jordan &Young, 1990
Calciopappus Gaardcr & Ramsfjell. 1954
C. caudattts Gaarder & Rams !jell. 1954
Coron~Jsphaera Gaarder, L977
C. medirerra11ea (Lohmann, 1902) Gaarder in
Gaarder & HeimdaJ. 1977
Michaelsarsia Gran. 1912 emend. Manron et al., 198-1
M. elega11s Gran emend. Man ton et al., 1984
Ophinster Gran. 1912
0. ltydroideus (Lohmann ) Lohmann emend.
Mnmon & Oares. 1983
Syracosp!laera Lohmann. 1902
S. cf. S. borealis Okada & Mclntyre, 1977

M .Cocluio,A.OJiveiro,J. Viumno: SubtropicaiiMnter guests, Ponugal. p. 19 - 26.

S. sp.l cf. S. epigrosa (Okada & Mcinryre, 1977)

Fiuza, A., Maccdo, M.E. & Guerreiro, M.R. 1982. Climatologicalspace and Lime variation of the Portuguese coastal upwelling.
OceanologicaActa, 5(1): 3140.
Frouin. R., Filiza. A.F.. Ambar. I. & Boyd, T.J. 1990.
Observalions of a Poleward Surface Cun·ent off the CoastS
o r Portugal and Spain during winter. Journal ofGeophysicalResearch, 95: 679-691.
Haynes. R. & Banon. D. 1990. A poleward flow along the Atlantic
coast of the Iberian Peninsula. Journal of GeophysicalResearcfi , 9S: 11425-11441.
Jordan. R. 1988. Coccolithophorid communities in the North·
East Atlantic. t:npublished PhD thesis, University of Surrey.
UK: 350pp.
Jordan. R. & Green. J. C. 1994. A Check-list of the Extant
Haptophyta of the World. Joum al of Marlue Biology. UK.
74: 149-174.
Jordan. R. & Kleijne, A. 1994. A classification system for living
coccolithophores. !11: A. Winter & W. Siesser (Eds).
Caccofithopf10res. Cambridge University Press: 83- 105.
Kleijne. A. 1993. Morphology, Taxonomy and Distribution ofeAtant Coecolithophorids (Calcareous nannoplankton).
Unpublished PhD thesis. Vrije Universiteit. TheNetherlands:
32 1pp.
Klein, B. & Siedler, G. 1989. On the origin of the A7.ores Current.
Jou11wl of Geophysical Research, 94: 6159-6168.
Mclnryre. A. & Be. A. 1967. Modem Coccolithophores of theAtlantic Ocean - I. Placoliths and Cyrtholiths. Deep-Sea
Research, 14: 561-597.
Perch-Nielsen, K. 1985. Cenozoic calcareous nannofossils. In :H. Bolli. J.B. Saunders & K. Perch-Nielsen (Eds). Plankton
Strarigraplry. Cambridge University Press: 427-554.
Pollard, R.T. & Pu. S. 1985. Structure and Circulation of theUpper Atlantic Ocean Northeast of the Azores. Progress in
Ocea11og,·aphy. 14: 443-462.
Rios. A.F.. Perez, P.F. & Fraga. F. 1992. Water masses in theupper and middle North Atlantic Ocean east of the Azores.
Deep-Sea Researcft. 39(3/4): 645-658.
Silva, J. 1992. Dependence of upwelling related circulation onwind forcing and stratification over the Portuguese northern
shelf. ICES Hyd. Comm. CM. 1992/C: 17.
Stramma.L. & MUller, T.J. 1989. Some observations of the Azores
Current and the Nort h Equa torial Current. Joumal ofGeophysical Research, 94: 3181-3186.
Vitorino. J. 1989. Circula~ao residual ao largo da costa 1'-.'W dePortugal durante a esta~ao de anoramemo de 1987. Anais do
Inst. Hidrograflco. Lisboa, 10: 25-37.
Winter, A .. Jordan, R.W. & Roth, P. 1994. Biogeography ofliving coccolilhophores in ocean waters. /n: A. Winter & W.
Siesser(Eds). Coccolithophores. Cambridge University Press:
161 - 177.
Wooster. W.S., Bakun. A. & McLain, D.R. 1976. The seasonal
upweUing cycle along the eastern boundary of the North
All an tie. Joumal of Marine Research. 34: 131 -141.

Kleijn.:, 1993
S. epigrosa Okada & Mcfnlyre. 1977
S. halldafii Gaarder ex Jordan & Green. 1994
S. familia Lecal-Schlauder, 1951
S. mofischii Schiller, 1925
S. nodosa Kamptner. 1941
S. 11oroitica Knappensbusch, 1993 emend. ortog.
S. orbicufus Okada & Mclntyre. 1977
S. nssa (Lecal) Loeblich & Tappun. 1968
S. prof011gata Gran ex Lohmann, 1913
S. pulchra Lohmann, 1902
Genus Umbellosphaera Paasche. 1955
U. renttis (Kamptner. 1937) Paasche, 1955
Family: CALYPT.ROSPHAERACEAE BoudreaiLx & Hay,
Genus

1969
CalyptrolitlziiW Heimdal. 1982
C. diverge11s (Halldal & Markali. 1955) Heimdal.
1982

Genus

Genus

Genus
Genus

Journal of Nannoplanklon Research, 22. I. 2000.

Syracofithus (Kamptner) Deflandre, 1952
S. da/maticus ( Kamptner, I 927) Loeblich &Tappan. I 966
Genera l ncertae sed is
Fforisplwera Okada & Honjo. 1973
F. pro[t111da var. oblongata Okada & M c l ntyre.
1980
F. profunda var. profunda Okada & Honjo. 1973
Polycrater Mat~lon & Oates. 1980
P. ga fapagensis Manton & Oatcs. 1980
Turrifillltls Jordan f!l al .. 1991
T. latericioides Jordan et al., J 991

For bibliographic references on species taxonomy see PerchNielsen (1985). Jordan & Kleijne (1994) and Jordan & Green( 1994).
Refer ences
Caehiio, M. & Moita. T. In press. Coccalitlms pelagicus, aproductivity proxy related to moderate fronts. Marine

Micropa/eontology.
Cachiio, M .• Oliveira, A. & Vitorino, J. 1998. Coccolithophore
assemblages from offshore Portugal. Unpublished
CODENET First Annual Workshop Report: 50-58.
Dias, C.M.A, Cavaco. M.H. & Pissarra. J. 1990. Observationof the Azores front in July 1987 and June 1989. /CES. C34:
15pp.
Fiuza. A. 1984. Hydrology and dynamics of the Portuguese
coastal waters. Unpublished PhD thesis. Univ. of Lisbon:
294pp.
Fiuza. A., Hamann, M., Ambar. I.. Rio. G., GonzaJez, N. &Cabanas, J. Subrnitted. Water masses and their circulation in
the Western Iberian Coast Ocean during May 1993. Deep-

Sea Research.

25